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Doppler shift estimation of MIMO-OFDM systems based on auto-correlation function of channel estimate.

机译：基于信道估计自相关函数的MIMO-OFDM系统多普勒频移估计

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摘要

Multiple-input multiple-output (MIMO) and orthogonal frequency division multiplexing (OFDM) techniques have been considered as a strong candidate for the next-generation - wireless communication systems, due to their well-known advantages in high data-rate wireless transmission as well as high frequency spectrum efficiency. In the mean time, channel state information (CSI) is required for precise detection and recovery of signals. Therefore, channel estimation plays a significant role in MIMO-OFDM systems. On the other hand, due to the high mobility of wireless terminals, Doppler shift (DS) can be one of the major side-effects of utilizing MIMO-OFDM techniques, which may lead to severe performance loss. Many schemes on DS estimation have been developed for broadband single-input single-output (SISO) systems. A commonly used method is to exploit the auto-correlation property of the channel impulse response (CIR) estimated by well-developed channel estimation approaches, which not only has high accuracy but also moderate computational complexity. Hence, we first investigate an efficient channel estimation method in this thesis. We will then focus on Jakes' model based DS estimation schemes, and further extend to independently identically distributed (i.i.d.) MIMO-OFDM fading channels with both Rayleigh and Rician distributions.;The second part of the thesis first studies the auto-correlation function (ACF) based DS estimation schemes for SISO-OFOM systems in Rayleigh fading channels, and then extends it to Rician fading channels by developing a new approach along with the analysis of its accuracy and complexity. Thereafter, we apply those approaches to MIMO-OFOM systems and present a few enhanced methods by using non-linear interpolation under certain circumstances. Detailed computer simulations and comparisons are performed, confirming that the proposed ACF based schemes give satisfactory estimation performance over i.i.d. Rayleigh or Rician fading channels with various channel conditions.;In the first part of the thesis, a training-sequence (TS) based least square (LS) channel estimation scheme is presented for MIMO-OFDM systems along with plenty of computer simulations and corresponding analyses. Experimental study shows that the CIR estimates obtained by the LS method are reliable under moderate channel conditions, and can efficiently be utilized for DS estimation.
机译：由于多输入多输出（MIMO）和正交频分复用（OFDM）技术在高数据速率无线传输中具有众所周知的优势，因此它们被认为是下一代无线通信系统的强大候选者。以及高频谱效率。同时，需要信道状态信息（CSI）来精确检测和恢复信号。因此，信道估计在MIMO-OFDM系统中起重要作用。另一方面，由于无线终端的高移动性，多普勒频移（DS）可能是利用MIMO-OFDM技术的主要副作用之一，这可能会导致严重的性能损失。已经针对宽带单输入单输出（SISO）系统开发了许多DS估计方案。一种常用的方法是利用通过完善的信道估计方法估计的信道冲激响应（CIR）的自相关属性，该方法不仅具有较高的准确性，而且具有中等的计算复杂度。因此，本文首先研究一种有效的信道估计方法。然后，我们将集中讨论基于Jakes模型的DS估计方案，并进一步扩展到具有瑞利和里奇分布的独立均匀分布（iid）MIMO-OFDM衰落信道。;论文的第二部分首先研究自相关函数（基于瑞利衰落信道中SISO-OFOM系统的DS估计方案，然后通过开发一种新方法以及对其准确性和复杂性的分析，将其扩展到Rician衰落信道。此后，我们将这些方法应用于MIMO-OFOM系统，并在某些情况下通过使用非线性插值来提出一些增强方法。进行了详细的计算机仿真和比较，确认了所提出的基于ACF的方案在i.d.d上给出了令人满意的估计性能。论文的第一部分，针对MIMO-OFDM系统，提出了一种基于训练序列（TS）的最小二乘（LS）信道估计方案，并进行了大量的计算机仿真和相应的研究。分析。实验研究表明，通过LS方法获得的CIR估计在中等信道条件下是可靠的，并且可以有效地用于DS估计。

著录项

  • 作者

    Zhu, Qin.;

  • 作者单位

    Concordia University (Canada).;

  • 授予单位 Concordia University (Canada).;
  • 学科 Engineering Electronics and Electrical.
  • 学位 M.A.Sc.
  • 年度 2009
  • 页码 104 p.
  • 总页数 104
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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